The desire to shrink the size of mechanical components, optical devices, and sensors to sizes obtained by the microelectronics industry has driven a significant amount of research in the field of micro-electro-mechanical systems (MEMS). Micromechanical devices are currently being considered for a wide variety of applications including uncooled infrared detectors, micro-actuators, chemical detectors, and completed mechanical systems. Currently the dominant manufacturing method for micro-devices is the microlithography approach used by the microelectronics industry. This approach works well for producing a large quantity of devices, however the ability to produce prototype devices is not as developed as the ability to mass-produce devices. The ability to simulate the response of micro-devices using finite element analysis (FEA) gives researchers insight into the behavior of devices before prototypes are developed or production runs occur as well as allowing the designer to optimize the desired response.
Photon detectors represent a class of MEMS devices that have been studied with great interest. Several different types of photon detectors are available including CCDs, microbolometers, thermopiles and pyroelectrics. Solid state infrared detectors must be operated at reduced temperatures from the ambient in order to reduce thermal noise. The infrared thermal detectors in this invention convert the incident radiation into heat which produces a change in the position of the micro-cantilever through bimetallic bending or other effects. The effects of several design variables on the bending of microcantilever structures is necessary for development of an improved response detector.
A xe2x80x9cfolded-legxe2x80x9d microcantilever thermal detector was fabricated using focused ion beam milling. This device was created as a compact, sensitive, thermal detector. A large collecting area (pad) was defined at the deflective end of a folded leg structure to maximize the energy absorbed. The purpose of folding the legs five times was to create a compact device that behaved thermally and mechanically as a larger device. The device with the legs folded five times is referred to as a pentalever. The collecting area is also the area used for optically measuring the displacement. The microcantilever detector was constructed of substrate having an upper side, lower side, fixed end, and deflective end, with the substrate having at least one leg interposed between the fixed end and the deflective end. Each leg has at least three essentially parallel leg segments interconnected on alternate opposing ends and aligned in a serpentine pattern with only the first leg segment attached to the fixed end and only the last leg segment attached to the deflective end. The preferred embodiment of the instant invention alternated leg segment coatings on the pentalever with coating applied to the top of the first, third, and fifth segments of each leg and to the bottom of the second and fourth leg segments. The deflective end may be coated or uncoated on the top and bottom.